Re: [PATCH 2/3, RFC] watchdog dev BKL pushdown

From: Arnd Bergmann
Date: Tue May 20 2008 - 04:33:22 EST


On Tuesday 20 May 2008, Christoph Hellwig wrote:
> On Tue, May 20, 2008 at 01:14:23AM +0200, Arnd Bergmann wrote:
> > The Big Kernel Lock has been pushed down from chardev_open
> > to misc_open, this change moves it to the individual watchdog
> > driver open functions.
> >
> > As before, the change was purely mechanical, most drivers
> > should actually not need the BKL.
>
> Actually I'd prefer to fix this for real.  This single open stuff aswell
> as same set of ioctls are duplicated all over the watchdog drivers.  We'd
> be much better off introducing a simple watchdog layer that handles this
> plus proper locking and convert drivers over to it gradually.

I fully agree, I thought the same thing when I did the patches. I remember
that Wim had a git tree doing this, which is still active at
http://git.kernel.org/?p=linux/kernel/git/wim/linux-2.6-watchdog-experimental.git;a=commitdiff;h=732c54027e6c866f98857c4a6d1c6c466459dcd5

Unfortunately, it hasn't seen much activitity over the last two years, and
the number of watchdog drivers seems to have exploded: I count 67 of them,
including some outside of drivers/watchdog.

Wim, was there anything preventing you from integrating the generic
watchdog layer back then?

Arnd <><
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/